The Associated Press reports that ZunZuneo, which is the Cuban slang for the hummingbird’s tweet, was created using $1.6 million [£960,000] originally earmarked for a project in Pakistan. Those that signed up used a text-message based social network and the documents revealed that “non-controversial” content would first be sent to subscribers before political content aimed at sparking uprisings would be introduced.

The users of the service were unaware that it was funded and created by an agency linked to the US State Department or that contractors from the US were able to gather personal data that could also be used for political means.

Pouring through the 1,000-plus documents also revealed that the scheme was organised “below the radar” by the US government and it used the US Agency for International Development [USAID] in order to hide the government involvement in the scheme.

USAID didn’t reveal who signed off on the deal, making a statement that read it is "proud of its work in Cuba to provide basic humanitarian assistance, promote human rights and fundamental freedoms, and to help information flow more freely to the Cuban people," who it said "have lived under an authoritarian regime" for half a century. It said the work was "consistent with U.S. law."

To cover its tracks, front companies were set up in Spain and the Cayman Islands in order to cover the money trail and CEOs were persuaded to get involved without being told that it was a US taxpayer-funded scheme.

"There will be absolutely no mention of United States government involvement," according to a 2010 memo from Mobile Accord Inc., one of the project's creators. "This is absolutely crucial for the long-term success of the service and to ensure the success of the Mission."

For over two years the service grew unfettered to around 40,000 users before officials in Cuba attempted to trace the messages sent using the system and ultimately break into it and it was closed in September 2012 when the government grant finished.